The ATP B3ZQ-S Clockwise, Mechanical Seal style pump is the Standard 4 x 3 Centrifugal Water Pump used for mounting to an independent SAE 5 engine in place of a transmission using a 1-3/8 10 Tooth Splined Shaft. This pump is GROOVED on both the suction and discharge side for easy removal and repair, and at 2500 RPM performs at a rate up to 800 GPM at 70 PSI. Have a SAE 4 motor you' d like to use with this? Try our SAE 5 to SAE 4 adaptor.